This invention relates to containers, and in particular, to a water bottle adapted for use with a dispenser.
Presently, water is sold for home, office or retail use in large bottles. Bottles of this type usually include a generally cylindrical body, a generally frustoconical top breast at the upper end of the body, and a tubular filling and dispensing neck projecting upwardly from the central portion of the breast. Bottles of this type usually are inverted and installed on a gravity-type dispenser. In order to enable the bottle to be used with standard filling equipment, the diameter of the neck of the body is small in comparison to the diameter of the generally cylindrical body of the bottle. Most water bottles of this type, termed “carboys”, are blow molded from a plastic such as polycarbonate, polyvinylchloride, polyethylene or polypropylene, and have a capacity typically of 3, 4 or 5 gallons. The molding is effected by extruding a hot plastic parison into a mold and by using compressed air to blow the plastic into a shape conforming to the mold. These bottles are designed for reuse, and may be of the type illustrated and described in U.S. Pat. No. 5,217,128, incorporated herein by reference. The typical duty cycle of such bottles is 20 to 50 recycles. The marketing system for the bottles filled with water includes delivery and pick-up services which require considerable investment and is considered to be quite labor intensive.
In recent years, large bottles imitating the shape of the existing cylindrical bottles have been formed of polyethylene terephthalate (PET). PET is recognized as a material which is superior in many respects to polycarbonate and polyvinylchloride for use in bottles and the like. PET is stronger than the more conventional materials and thus a more economical and lighter weight bottle may be produced by using PET, since less material is required to make a bottle of given size and strength. Also, PET has virtually no effect on the taste of the water or other beverage, and has superior clarity and transparency.
PET bottles, however, are not useful in a returnable mode because PET has limitations regarding temperature above 70 degrees C./160 degrees F. This does not allow the bottle made of PET to survive repeated washing at normal elevated temperatures required for sanitation purposes. Furthermore, such bottles tend to be quickly degraded by the rigors of outdoor storage and exposure to high temperatures of delivery trucks in the hot sunlight. Also, the sale of water in one-way 5 gallon PET bottles has been limited due to the weight of resin used in making the container and the consequent cost of the bottle when it is used once and then recycled.
In small one-way PET water bottles, the weight of resin per liter of contents drops from approximately 50 grams/liter to 20 grams/liter as the bottle size increases from 250 ml to 2 liters. It makes sense that the larger the container, the more efficient the use of resin would be. However, early designs of one-way PET carboys did not achieve this improvement and required 450 grams for a 5 gallon carboy, i.e., 24 grams/liter, mainly because of vacuum problems associated with dispenser-mounted bottles.
Lightweight PET carboys can collapse under the vacuum created by water as it is dispensed from the bottle and can fall off the dispenser spilling water out of the bottle onto the floor. The vacuum within the carboy can reach approximately 50 millibar (about 1 psi). This is not a large pressure, but applied to the side of a cylindrical container, it can produce a force of close to 50 pounds on a 5 inch wide×10 inch high area on the side of the container. In an attempt to solve this problem, designers have reduced the diameter of the cylinder carboy to 9 inches to make the carboy more rigid. However, this requires the carboy to be taller for the same volume and increases the amount of resin used.
It is a primary purpose of the present invention to produce a bottle for water which is light in weight, inexpensive, useful for one time use, and readily acceptable for present transportation configurations and dispensing equipment.